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[Gordon Brinton]

I want to buy 2 ETX-35P mains for small club work with a 4 piece rock band. I may be able to squeeze enough out of my budget to buy one ETX-15SP sub, but not two. My idea is to play the 3-way top boxes full range, (because they go down to 48 Hz,) and play the sub from say 100 Hz on down. Here is where the problem begins...

A fellow soundman tells me that running the tops full range will cause phase problems between the sub and the tops (even though they all have 15's) due to different crossover points. He says the room will have more/bigger nulls and modes than it would without the sub.

Is this so? Would I get more low end using those particular tops full range with no sub or running the tops high-passed with only one sub?

Keep in mind that the tops will always be on poles to get the horns up high.

Thanks.

[Stephen Kirby]

Any time you have more than one source you will get interference, which will cause some cancelation at points in space.  Because of the wavelengths involved, you will often get more apparent bottom evenly distributed around a bar or small club with a single point source of bass.  Especially when you're shoved into a corner or some other odd place instead of a nice centered theatrical stage.

Curious why you are looking at full range cabinets and then adding subs.  What about smaller tops like ETX12Ps over a pair of subs?  Putting full range speakers up in the air robs them of the boundary reinforcement of the floor and makes getting a solid bottom more difficult without having real serious gear.  For a band, it's usually about getting the vocals across, some assistance with distributing the guitars and keys around the room and having a nice solid kick integrated with the bass.  The mid bass you'd get from an elevated 15 is usually already plenty strong from the stage.  Unless you're one of those groups where there's no amps on stage and everything is direct from modelers and e-drums.

[Mac Kerr]

A fellow soundman tells me that running the tops full range will cause phase problems between the sub and the tops (even though they all have 15's) due to different crossover points. He says the room will have more/bigger nulls and modes than it would without the sub.

Anytime you have multiple sources with the same signal you will have destructive interference. Whether that is a problem or not is totally a judgement call. Listen to it, does it offend you? If yes there are actions you can take to improve the situation, if not you're good to go.

With subs the cancellations in the room are going to be dominated by reflections, there is very little you can do about that.

Mac

[Gordon Brinton]

...Curious why you are looking at full range cabinets and then adding subs.  What about smaller tops like ETX12Ps over a pair of subs?...

That would be four cabs to buy...well, beyond my budget. Just trying to get the most bang for my buck. I figure I can occasionaly run them without subs.

Here is a new approach.
Since subs act as one when placed within 1/4 wavelength, I could run one top box full-range while pole mounted above the sub. The 15 in the top box should couple with the sub. The top box that stands alone (other side of stage) could be set to high-pass above 100 Hz. That way, all frequencies below 100 Hz are seemingly coming from one point in the room, but I get the benefit of two 15's playing lows. +6dB.

No?

[Tim Weaver]

Buy the bigger cabs, use them for a while until you can buy the 18" sub.

Use that combo for a while until you save up enough to buy another 18" sub.

Now you have a system. Use the internal crossovers and rock out

[Gordon Brinton]

Buy the bigger cabs, use them for a while until you can buy the 18" sub.

Use that combo for a while until you save up enough to buy another 18" sub.

Now you have a system. Use the internal crossovers and rock out

I'm kind of liking the idea of the 15's being smaller and lighter. I sometimes load-in and set up myself.

[Scott Olewiler]

I want to buy 2 ETX-35P mains for small club work with a 4 piece rock band. I may be able to squeeze enough out of my budget to buy one ETX-15SP sub, but not two. My idea is to play the 3-way top boxes full range, (because they go down to 48 Hz,) and play the sub from say 100 Hz on down. Here is where the problem begins...

A fellow soundman tells me that running the tops full range will cause phase problems between the sub and the tops (even though they all have 15's) due to different crossover points. He says the room will have more/bigger nulls and modes than it would without the sub.

Is this so? Would I get more low end using those particular tops full range with no sub or running the tops high-passed with only one sub?

Keep in mind that the tops will always be on poles to get the horns up high.

Thanks.

These speakers are beasts at 98 lbs. It's all I can do to sit one on top of a 32" high single sub. If you think handling the 18" sub is going to be hard at ground level try lifting one of these up onto two ETX subs stacked at 38". And the horn will still not really be high enough if you're on the ground.  Getting one on a pole by yourself would be quite a feat.

They are great full range speakers but you do need to get the mid-range over peoples heads to take full advantage of them.  If you can manage to do that on poles, great.   As far as using just one sub, you could try a very low crossover point between your tops and your subs, maybe something like 70hz or lower so the sub is doing much less of the work.  If it doesn't work, save up and buy more subs later.

I just my pair of these full range with a band last weekend at a backyard party at my house.  They did OK on the low end but I wasn't pushing a lot of volume.  I'm not sure single sub would even add much to these. I think at least 2 subs per top is the minimum to fully utilize the sub. And I would still choose the 18' to get the extra height, but I totally get not wanting the additional 23 lbs.  I find once you get above about 50 lbs even 10 lbs makes difference.

[Stephen Kirby]

I'm kind of liking the idea of the 15's being smaller and lighter. I sometimes load-in and set up myself.

All the more reason to have smaller boxes in a modular system.  I can't imagine moving 15" 3 ways around by myself, much less putting them up on poles.  Scott's observations are good.  My DRS112s are about as much as I want to deal with by myself.

Again, the only advantage I can see to these boxes is being more full range and rated as slightly louder.  Although given the same HF driver as the ETX12p I can't see where it would be louder in the real world.  The 2" driver in the DSR outruns it in real world pegged operation.  And if you ask around to the distributors on this board, you may find that you can get a pair along with DXS15s for similar price to the 3 ETXs at you local Banjo Hut.  And the Yamaha stuff has a bit less marketing inflation on the specs, so you'd have to listen to them to know why I picked the DSRs over the ETX for my band use.

[Steve M Smith]

I can't imagine moving 15" 3 ways around by myself, much less putting them up on poles.

When I have to do it myself, I do it horizontally on the floor first then put it upright.


Steve.

[Ivan Beaver]

A fellow soundman tells me that running the tops full range will cause phase problems between the sub and the tops (even though they all have 15's) due to different crossover points. He says the room will have more/bigger nulls and modes than it would without the sub.

I bet most people who talk about "phase problems" would not know it if it hit them in the head. But it is "cool" to appear to know what you are talking about.

And not to be "mean" (just honest), most people don't even know what a "good" phase trace looks like.  So how would they know if it is bad?

Your "phase problems" START with just the drivers in the full range box and the different distances to the listeners.

And when you add a second cabinet-it gets even worse.  And if you have instruments on stage that produce sound (guitar amps-drums-monitor etc) you have EVER MORE "phase problems".

At this rate you might as well go home because it is "so bad"-------

How big of a problem is it-depends on who  you talk to.

Or simply putting a speaker in a room causes "phase problems".

A sub will "possibly" allow you have more bass-or it could cancel at some freq.

It all depends on how the system is setup/aligned etc.

There is no simple way to know without measuring.

There are a lot of variables that are not easy to answer on a forum.

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